Actin is cleaved during constitutive apoptosis

Abstract

Proteases play an important role in the programme of cell death by apoptosis but little is known of the substrates cleaved, particularly in constitutive models of this type of cell death. Neutrophils spontaneously undergo apoptosis in culture without requiring external stimuli. During this process we found biochemical and immunochemical evidence for the cleavage of membrane-associated actin, a component of the cytoskeleton that links polymerized actin to the plasma membrane. Cleavage occurred at a single site at the N-terminus, between residues Val43-Met44, site devoid of a consensus motif for cleavage by cysteine proteases of the interleukin-1β-converting enzyme (ICE)-family. Whereas actin ..